Has the democratic tide turned in the western world? Will the forces of extremism come to power in ever more countries? Is Europe heading back to the dark valley of the 1930s?

Understanding the changes taking place in the politics of the western world is not easy. Scholars of politics are divided on why the centre is weakening. Some believe that immigration and more cultural diversity are driving voters away from mainstream parties while others focus on economic factors and inequality as the main explanation.

Whatever the reasons, most of the attention has been on the populist right. Hard-left parties have benefited from recent trends, but to a lesser degree than their counterparts at the other end of the political spectrum. One reason is that they cannot claim successes when they have had power. In Greece, the Marxist-leaning Syriza party has lagged its main rival in opinion polls since within a few months of taking office in 2015 and looks set to be voted out of power next year. The on-going tragedy of oil-rich Venezuela has reinforced the hard left's long historical record of disastrous economic mismanagement.

The hard right has been electorally more successful and, as such, poses a bigger threat to liberal democracy in Europe and elsewhere. Hungary, Poland and the US are led by people outside the centre-right and centre-left mainstream that has dominated politics in the west for decades. For Europe, perhaps the most significant development has been the coming to power of such a government in Rome earlier this year.

I'll return to Italy presently, but to understand the rise of reactionary-right and where it could lead, it is important to consider the nature of these movements, not least because there has been a tendency to label them as "fascist" with little serious thought as to what that actually means.

While the reactionary-right of today shares some features of the fascism of yesteryear, there are more differences than similarities.

Perhaps the most important difference is that the reactionary-right of today is isolationist - it wants to build walls, harden borders and turn its back on the world. Fascists were very different. They believed in marching across borders, conquering their neighbours and creating empires.

Fascists believed that conflict brought out the essence of man and was, thus, the natural state of things. The modern populist right does not glorify ultranationalist blood-letting and not even the wildest fringes of such parties advocates militaristic imperialism. On the contrary, they are more likely to criticise power projection abroad - think of Donald Trump's opposition to the US military presence in Afghanistan before he became president, underpinned by his belief that US blood and treasure should not be expended sorting out foreign problems. He has not changed since taking office.

Fascists' imperialist impulses were driven not just by the desire for territorial aggrandisement, but also by a belief that the subjugation of others was proof of national superiority and virility. Eugenics - the belief that there was a scientific basis for a hierarchy of races - had wide currency in the early 20th century across much of the political spectrum. Fascist thinking was more influenced by eugenics than any other belief system of the time.

The racism that exists on the populist right today is not rooted in the pseudoscience of eugenics, but has more to do with a reactionary tendency to view those who are different with suspicion and/or as a threat. In Poland and Hungary, this instinct partly explains why both countries have refused to participate in an EU-wide scheme to house refugees who have come from outside the bloc.

The differences between the reactionaries of the right today and fascists of the past extend beyond war and race. They include how states are ordered internally. Here, the distinction between authoritarianism and totalitarianism is important.

Fascists believed that the state was everything. Nothing of any significance - politically, socially and economically - could happen without the involvement or at least the blessing of the state. For fascists, there was no such thing as independent institutions or civil society organisations. There was only the state and "the people".

Authoritarian regimes come in many shapes and sizes. They use as much repression as is deemed necessary to retain power, but do not have an ideological belief in total control of everything that happens in the public sphere.

The hard-right parties of today share a belief that they are the authentic voice of "the people" and they attempt to silence those who disagree with them by various means, but they are not totalitarian. While most of them seek to curb independent institutions and criticism, they are not proposing to cancel elections, ban political parties other than themselves or take control of the internet.

Victor Orban's Hungary is perhaps the best example in Europe of an authoritarian-leaning government of the reactionary-right. Orban has used heavy-handed tactics to marginalise those with different views - this weekend it looks as if the Central European University will be forced out of Budapest. He has used government contracts to bolster his allies in business and undermined media organisations that do not support him.

It is perfectly possible that Hungary will become more authoritarian over time, but that is not inevitable. Autocratic regimes around the world, which range from partially democratic to outright autocracies, sometimes become more democratic over time and sometimes less so. Many factors are involved, but history certainly does not show an iron law that non-democracies always become totalitarian.

The differences between fascists and today's reactionary-right are likely to be important if the latter do come to power in more European countries. Instead of a return to an age of industrial war and death camps, the future might well look like other parts of the world today where authoritarian regimes rule.

One does not have to look much beyond Europe's doorstep to find them. Morocco and Algeria are authoritarian states. They are internally repressive with poor human rights records. The two countries also have the hardest of borders. Along their 1,600km frontier, there is not a single legal crossing point. Unsurprisingly, given how hard their border is, they do little trade with each other. This is one reason they are so much poorer than their neighbours.

That brings us back to Italy. Its elections last March may prove to be a watershed moment. It brought a populist-nationalist government to power. Some of its leading figures blame outsiders for all of the country's many woes. Italy would be great again were it not for eurocrats in Brussels, international financiers and immigrants.

The new government is promising a swathe of tax cuts and new spending initiatives. It is doing so against a backdrop of extreme economic, fiscal and financial fragility. Italy is very close to entering the same spiral that brought collapse in Greece and almost brought down the euro.

As one of the 10 largest economies in the world, a Greek-style collapse in Italy would have enormous implications. It would almost certainly trigger a deep recession across the continent and the outcome could easily be much worse.

The financial collapse of Italy would also likely lead to a break-up of the euro, something that would raise questions about the future of the wider European integration project.

Europe's future may be to become more like the rest of the world, with countries becoming more closed and inward-looking, and a range of political regimes ranging from democratic to authoritarian. That may not be as bad as the 1930s and 1940s, but it is surely a future that few could really wish for.